The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/a40efde9a68ead4d71421854fda2409e1cc7b053

commit a40efde9a68ead4d71421854fda2409e1cc7b053
Author: mkwst <mkwst@chromium.org>
Date: Fri Apr 08 21:51:55 2016

Fetch: 'password' credentials mode should include credentials.

I am not going to admit how long it took me to find this bug. Because it
was a long time and involved me installing Fiddler to verify that
chrome://net-internals wasn't lying to me because OBVIOUSLY the data
wasn't being posted to the server even though net-internals said it was
and ugh.

'password' should act like 'include' (see #2 in [1]). We should include
cookies in either mode. *sigh*

[1]: https://w3c.github.io/webappsec-credential-management/#monkey-patching

BUG=599597, 601923 
R=horo@chromium.org, estark@chromium.org

Review URL: https://codereview.chromium.org/1868253002

Cr-Commit-Position: refs/heads/master@{#386212}

[modify] https://crrev.com/a40efde9a68ead4d71421854fda2409e1cc7b053/third_party/WebKit/LayoutTests/http/tests/credentialmanager/passwordcredential-fetch.html
[add] https://crrev.com/a40efde9a68ead4d71421854fda2409e1cc7b053/third_party/WebKit/LayoutTests/http/tests/credentialmanager/resources/echo-cookies.php
[modify] https://crrev.com/a40efde9a68ead4d71421854fda2409e1cc7b053/third_party/WebKit/Source/modules/fetch/FetchManager.cpp